Self-steering device



July 15, W47. H. F. ROST ETAL SELF-STEERING DEVICE Filed July 31, 1940 5 Sheets-Sheet l INVENTORS tun m mun w uuwd 0 n w A b nE R a a 1 .l H m' E m HKfiMB July 3 5, 1%7.

H. F. RUST El AL SELF-STEERING DEVICE Filed July 31, 19 40 5 Sheets-Sheet 2 lNVENTORSZ Hal e Fabian R s K31 Harry mumu Stan Daniel Vi fen Per H BY 'w-aem ATTORNEY Elas Claesson July 1, 1947.

H. F. ROST ETAL.

SELF-STEERING DEVICE Filed July 31, 1940 5 Sheets-Sheet 3 BNVENTQEI 1 (2 Fabian: Re Kan- Han-Y Trmmn Stem Da l Vi THEE? ATTQR NEY H. F. ROST ETAL SELF-STEERING DEVICE 5 Sheets-Sheet 4 Filed July 31, 1940 PNVNTDR$ H e Fabian PO T Kasr Haw Stem Da 2:

THEIR AT ORNEY E, 1947. H. F. ROST EI'AL 2,424,193

SELF-STEERING DEVICE Filed July 31, 1940 5 Sheets-Sheet 5 BNV NTORS2 He]. e Fabian Po Kai- 1 H y W Ste. wn /77 p H 'y Elias C a wn as light, infrared or radio waves.

Patented July 15, 1947 SELF-STEERING DEVICE Helge Fabian Rest, Djursholm, Kai-1 Harry Thunell, Nockeby, Sten Daniel Vigren, Stockholm, and Per Harry Elias Claesson, Jakobsberg,

Sweden Application July 31, 1940, Serial No. 348,702

- In Great Britain August 16, 1939 14 Claims.

to take over the control for automatic seeking and/ or following of the target.

The present invention refers generally to a self-steering device for a carrier of a charge of explosive, for example an aerial bomb, torpedo or aircraft and comprises a seeking or scanning device installed on said carrier to scan for a target in a plurality of directions and provided with a device that can receive radiant wave energy, for example light, infrared or electromagnetic waves and thereby discriminate between the same kind of waves emitted from or reflected from said target and its surrounding medium.

The general principle of the invention'is based on the fact that the target and its surrounding medium should have different powers of absorbtion and reflection of electromagnetic waves such Said powers of reflection and absorption differ for different wave lengths.

Depending upon the target, its location, its colour, its illumination, its power of reflection of waves with respect to the surrounding medium and depending upon the penetration of the waves through the atmosphere with haze, dust, fog or smoke the invention can equally well be adapted for visual, infrared or electromagnetic waves.

If the visibility is good during day time, the target can reflect light from the sun directly or indirectly. The scanning device can eventually be provided with a filter to transmit only polar.. ized light, because by means of such a filter undesirable reflections from, for example, water surfaces are eliminated.

If the day is hazy or in order to obtain sufficient contrast between the target and its surroundings, infra-red rays alone can be used with advantage and recorded by the scannin and ceiving means simply by using a suitable filter in the scanning device. The infrared ray from the funnels of a ship or the exhaust from an explosion motor may during dark hours be a sufllcient source of emission of rays for locating the target.

If the visibility is poor, the weather cloudy or at night, radio waves can be used that can be transmitted from the torpedo, bomb, aircraft or the like and reflected by the target or its surrounding medium, and the reflected wave beams be received through scanning and receiving devices by one or more wave receivers installed on the bomb or the like. The target can be illuminated or struck by waves from another source than that of the sun, for example a light bomb can be dropped and caused to emit light which the target can reflect particularly at night;

Normally the bomb should initially be given such a direction from'the airplane, the warship or from the ground towards the target that the bomb should have onl to follow said target,

If the visibility is poor or if the direction of the bomb towards the target can be only approxlmate, the torpedo or bomb can be equipped with a hunting or searching device for general scanning to first locate the target and then to follow it.

The invention will be more fully understood and described in connection with the accompanying drawings which by way of examples serve to illustrate the invention.

Fig. 1 is a partly sectional side elevation of a bomb tobe dropped from an aircraft.

Fig. 2 is a sectional front view of the bomb shown in Fig. l at the line AA.

Fig. 3 is a diagrammatical view showing. for example, the horizontal surfaces covered by four scanning beams and a target shown within said beams.

Fig. 4 is a diagrammatical view of the general principle of the scanning, receiving and steering devices.

Fig. 5 is a diagram showing the principal mechanical and electrical devices and their connections with respect to seeking, scanning, receiving and steering devices of a bomb as Well as an electric generating source.

Fig. 6 represents a transmitting arrangement of electromagnetic waves.

Fig. '7 represents a receiving device for electromagnetic waves.

Fig. 8 represents in diagrammatic form a receiving device for ultrashort Waves instead of the photocell arrangement shown in Fig. 5.

Fig. 9 represents an excentrically rotating scanning device instead of the four scanning tubes and photocell shown in Fig. 5.

Fig. 10 represents in modified form scanning, receiving and steering devices in which the scanning device is provided with lenses, special scanning disc and opaque screen for spreading the rays received on the photocell. Instead of motors for driving the rudders relays are used to operate same.

Fig. 11 is a front view of the scanning disc and the collector rings shown in Fig. 10.

Fig. 12 is a curve showing a double swinging movement made by a bomb equipped as in Fig. during seeking operation.

Fig. 13 is an abbreviated diagram similar to that shown in Fig. 10 with the difference that two photocells and two amplifiers are used, each set scanning in two opposite parts of the target.

Fig. 14 is a front view of the scanning disc and collector rings shown in Fig. 13.

Fig. is a diagrammatic side view of an irisshutter regulating device for the scanning device and combined with a simultaneous adjustment device of the distance of the contacts associated with a pendulum to limit the swinging angles of a bomb in searching operations while falling.

In Fig. 1 and Fig. 2 l is the bomb shell. 2 and 3, 4 and 5 are scanning tubes, eventually provided with lenses, filters and opaque screens to only let through infrared rays of the desired wave length. 6 is a photocell for receiving the waves entering through the scanning tubes 2, 3, 4 and 5. l is a transmitter of electromagnetic preferably ultrashort or micro radio waves. 8 is a preferably parabolic reflector in the focus of which the transmitter and antenna is situated. 9 and ID are oppositely located fixed planes followed by rudders II and I2, simultaneously movable about axle l5 and I6 and controlled by slow acting wormgear l9, driven by motor l3. The axles l5 and I6 can be connected by suitable gear couplings so that they can move simultaneously. Eventually the rudders l I and I2 can be attached to the same shaft, if location of parts so admits.

l1 and 18 are shafts provided with rudders at right angles to rudders l I and I2. The shafts and rudders l1 and I8 are controlled by slow acting wormgear 20 and motor I4. Shaft I6 is provided with a, gear 2| which by suitable additional gears can be coupled to shaft I 5. 22 is a generator driven by propeller 23 to supply the necessary electric currents to the equipment contained in the bomb. 24 is a continuation of the generator shaft carrying a disc 25 provided with an opening 26 in front reflector 2'I. oppositely is located also reflector 29. In front of scanning tubes 4 and 5 are also located reflectors that can reflect the entering beams such as 29 and y on photocell 6. 21 and 28 reflect rays 29 and 30 when said opening 26 passes successively said reflectors.

In Fig. 1 and Fig. 3 29 and 30 are two oppositely situated scanning beams of waves entering scanning tubes 2 and 3 from a plane at right angles to the beams. 3| and 32 are two other similarly situated scanning beams entering through scanning tubes 4 and 5. 33 is the target shown in the beam 32, while the dotted line 33 shows the target, for example a ship symmetrically situated with respect to all four beams. The four beams are preferably located symmetrically in the corners of an equilateral square.

Instead of being provided with only one photoelectric cell 6 common to all four tubes, each or every two oppositely located tubes can be provided with a photoelectric cell or with an electromagnetic short wave receiving device, for example a magnetron, a klystron or other device for the reception of electromagnetic waves with a wave length of, for example a few millimeters or centimeters up to a. few meters.

Eventually electromagnetic or Herzian wave receivers of ultrashort wave lengths can be used to receive waves of the longer infrared waves which are overlapping the shortest Herzian wave range, 1,000,000 A. to 5,000,000 A. and vice versa.

If visible or infrared rays can penetrate to the scanning device of the bomb, or if an electromagnetic wave can be transmitted from a suitable location, the bomb does not need to emit waves itself. If, however, the visibility is poor or if electromagnetic waves cannot be emitted from such a place that waves reflected from the target can be received on the bomb, said bomb must have its own transmitting device. The receiving device for the reflected wave beams can be of the same kind as that of the transmitting device.

The devices according to the invention are so arranged that equal amount of light or wave energy is obtained in the oppositely situated scanning devices 2 and 3 from scanned surfaces 29 and 30 and in scanning devices 6 and 4 from scanned surfaces 32 and 3 I located at right angles to scanning devices 2 and 3, precisely when the target is symmetrically located with respect to the two or the four beams.

In Fig. 4 is shown in a simple form the general principle of the invention. 2 and 3 are two scanning tubes, each one with its wave receiver, for example a photocell or electromagnetic wave receiver 34 and 35 respectively. 36 and 31 is a potentiometer connected in series with the wave receivers. The potentiometer is eventually connected through an amplifier 39 and to a polarised relay 40 doubly biased and provided with armature and contact springs 47 and 4'! which can make contact with contact 42 or 42 and any one of contacts 43, depending upon in which direction the current passes through the winding of the polarised relay. v44 is in this case a direct current motor with its field winding 45, 4| is a direct current source. The motor 44 rotates in one or the other direction depending upon if the armature of the polarised relay is energised in one or the other direction. The shaft of the motor is provided with a worm gear 46--|9, whereby gear I9 is connected to a shaft IS on which are fixed rudders H and I2.

The operation of the device takes place in the following way. If in the beginning of the scanning there should be no foreign object in the way of the beams except, for example, the sea the intensity of the reflected waves from said sea in both beams is of the same magnitude and the currents through resistances 36 and 31 from battery source 38 will be alike and no current will pass through the polarised relay which will re main deenergised.

If, however, an obstacle like a ship 33 enters into the field of beam 29 the intensity of light or other waves reflected from the obstacle is increased or diminished, depending upon its colour or physical properties. The reflected waves in beam 29 are increased in the particular case shown in Fig, 4 over those reflected by beam 30 which strike the surrounding medium. This variation in the intensity of the two beams cause a heavier current through resistance 36 than through resistance 31, causing a difference of potential between the extremes of the potentiometer. A current will then flow through relay 46 causing its armature to make contact, for example, with contact 42, thereby causing motor 44 to rotate in a certain direction and the rudders Hl2 to move, thus causing a change of direction of the bomb and scanning tubes until the ship 33 is symmetrically located at equal distances between the beams 29 and 30. When the current through resistances 3B and 31 again are of the same magnitude, the motor 44 is stopped and the bomb will afterwards automatically keep the target in symmetrical position between the two beams, until the target is hit.

Should the target not be located in the plane passing through the scanning tubes 2 and 3 but on one side of said plane, two other scanning tubes at right angles and an additional device as that shown in Fig. 4 should be used. See Figs. 1, 2 and 3. In such a case four symmetrical beams are used as shown in Fig. 3 and two rudders at right angles to each other will keep the target in the center of the four scanning beams as soon as the target is located in any of the beams.

In order to limit or regulate the field of vision of the scanning device, the tubes can be provided with adjustable iris-shutter devices that, if a bomb is dropped from a certain altitude, can limit the vision to a certain portion of the surface to be scanned and afterwards gradually increase the scanning view as the bomb is drawing near the target. Such an automatic shutter device can be controlled by a timing device to be started a certain time after the dropping of the bomb.

Instead of using two ph'otocells or two electromagnetic wave receiving devices as shown in Fig. 4, only one cell or wave receiving device is preferably used as shown in Fig. 5.

Normally it is sufflcient that the target is only approximately located, for example from an airplane and the bomb dropped in such a direction that the target comes within the field of action of the scanning tubes.

If such an aiming is not possible and if the visibility is impeded and the bomb has to be dropped from a bomber at considerable height above a certain target, it is suflicient to know the approximate geographical location, such as longitude and latitude, of the target, in which casethe airplane can be directed to the same approximate geographical location to drop the bomb.

In one embodiment of the invention the bomb can itself seek the target, if said target should not be within the field of vision of the scanning device in which case the bomb is directed by its rudders in two different zig-zag movements at right angles to each other, whereby the scanning devices can cover an extensive surface. When the target has been found, the zig-zag movements cease and th torpedo or bomb follows the target in before described way.

By installing a timing device the zig-zag movements and the seeking should not start until the bomb reaches a certain lower altitude, suitable for scanning. During the fall of the bomb a small propeller can drive a dynamo to supply all the necessary currents needed for the operation of the device. Eventually dry batteries can be used as current sources.

Fig. 5 shows a device in which the scanning can be done partly by zig-zag movements and partly by ordinary scanning, and when the target searched for is located, the bomb follows the same by means of th ordinary scanning and following device. In Fig. 5 same numbers represent same or similar devices as in previous figures. 50

- peller which drives the gear 60.

is an electric contact to be closed by a. known timing device (not shown) to be started when the bomb has been dropped or started on its way. The closing of contact 50 closes the circuit of the field winding 49 of dynamo 22. supplying the necessary power by means of propeller 23, which rotates due to the air resistance when the bomb is falling.

Although in Fig. 5 current sources 4| and 99 are shown as individual current sources, the necessary current is understood to be supplied from dynamo 22 shown in the drawing. 5| is a worm on the shaft of the dynamo or of the pro- On the shaft of the gear are located cam wheels 6| and 62 which upon being rotated open contacts Bl-BS and 6'|--68 respectively and close contacts 6364 and 68-41 respectively. Cam wheel Si is provided with a plurality of cams to operate relays R6 and R1 and steering rudder H--I2 to make th bomb swing a determined number of times in a certain direction for rapid scanning purposes. On the same time as the cam wheel 6i revolves once, the other cam wheel 62 emits only one impulse, operating relays R8 and R9 and steering rudder ll-I09 to make the bomb swing once for slow scanning in a direction at right angles to the previously described scanning movement.

In the described way a certain extended surface is scanned after the bomb is dropped, for example, over a warship at sea until the ship is located in one of the scanning tubes. The operation of scanning the target and then following it takes place in the following way.-

As soon as the bomb has been dropped from an aircraft and the contact 50 closed, the generating device 22 delivers the primary power for all electrically operated devices on the bomb.

If, however, the bomb is dropped at high altitude more or less above the known geographical location of the target, without driving and aiming. the following operation takes place.

The shaft 83 is rotated by propeller 23 and drives wormgear 5l6ll and cam wheels 6| and 62. Spring 64 then connects ground to contact 63 and relay R6 over the following circuit: Ground, contacts 64l53, contacts 65R3, winding R6, battery 99. R6 is energized and starts motor 44 in known way, whereby rudder'll-l2 is operated in one direction via the worm gear 46-49. Instead of motor 34 wormgear 46-49 and relays R6 and R1 direct operation of the corresponding rudders an be made in known manner by means of, for example, a polarized relay with armature in the form of a rudder.

When spring 66 again makes contact with contact 65, relay R1 is energized over the following circuit: Ground, springs 64-65, contacts l0' 9R3, relay Rl, minus potential. Relay Rl energizes and R6 deenergizes. The polarity of currents of motor 44 and field coil 45 is reversed and the motor, after stopping, rotates in the opposite direction, moving the rudder lll2 also in the opposite direction.

The bomb is thus caused by the rudder H-l2 to make a zig-zag swinging movement in, for example, the north-south direction.

When on the same time the other cam wheel 62 is rotated, spring 61 is caused to make alternate contacts with 66 and 68 and in a way similar to that previously described. Relays R8 and R9 are alternatively energized and deenergized,

whereby the motor. I06 is caused to run in one or the other direction, on the same time moving the rudders I0l l09 in one or the other direction.

By this latter movements of rudder IIl1--I98 the bomb is simultaneously caused to make an east-west swinging movement during the same time as the bomb is making 15 complete northsouth swinging movements if, for example, cam wheel 6| has I cams and cam-wheel 62 only one cam. By the described combined north-south and east-west zig-zag swinging movement of the bomb the scanning device 23 and 4-5 have time to scan an extensive surface of the sea.

The scanning and following-operation takes place in the following way: Apart from the scanning tubes 2 and 3 and reflectors 21 and 28 there are two more scanning tubes and reflectors at right angles to tubes 2 and 3, as shown in Figures 1 and 2. Upon rotation of disc 25 the hole 98 will successively pass the 4 scanning tubes and let rays or light pass through to photocell or other sensitive device 8. Simultaneously with the passing of hole 98 in front of scanning tubes 2-3 and 4--8 the collectors 89-12 will successively connect condensers 8| and 82 and 89 and 99 to the general circuit controlled by the photocell or other sensitive device 6. Condensers 8| and 82 correspond to scanning tubes 2 and 3, while condensers 89 and 98 correspond to scanning tubes 4 and 5. If the same intensity of waves or light is received through tubes 2 and 3 or through tubes 4 and 8 condensers 8| and 82 obtain equal charges of electrical energy, but of opposite polarity from minus potential 4| over a grid leak I21 and amplifier 39. The condensers 8| and 82 will discharge in opposite directions through the primary winding I80 of the transformer IIIIl-IOI, while the condensers 89 and 99 will discharge through windings 93 and 94 of the polarized relay RI. 9| and 92 are amplifiers that eventually are inserted in the circuits of relays R2 and RI respectively.

If, however, the light received or waves reflected through the four scanning tubes should not be the same, due to the fact that an object, for example, a war ship enters into the field of vision of scanning tube 2, the current through photocell 8 will vary proportionally to the variation of waves received through tube 2 in which the warship is sighted and through tube 3 in which the seaonly occupies the field of vision. The condensers 8| and 82 will now be difierently charged every time the scanning hole 98 passes scanning tube 2 or scanning tube 3.

If during the rapid north-south swinging of the bomb condenser 8| receives a greater charge than that of condenser 82 due to the fact that more light or waves are reflected from the warship than from the sea alone, the resulting charge of the condensers 8| and 82 will discharge through the primary I98 of a current impulse transformer, and said discharge impulse induce a current impulse in opposite direction of the secondary IIII of said current impulse transformer. This induced current impulse will pass through the windings of polarized relay R2, causing said relay to cause its armature 81 to make momentary contact with contact 88. The following circuit is then closed: Ground, contact 81-88R2, contacts 8'1'R3, relay R4, minus potential 99. Slow to release relay R4 is then energized, closing its contacts |'--2R4. A ground short circuit is then placed on winding of relay R5 so that R5 cannot energize until armature 81R2 breaks its contact with contact 88 when the ground short circuit of relay R5 is opened. Relay R5 energizes now over the following circuit: Ground, I'--2'R4, winding R5, resistance I02, minus potential 99. R5 remains energized as long as slow to release relay R4 is energized. Contact I'2'R5 is closed preparing the circuit for relay R3.

If the bomb now swings over on the other side and the rays or waves received through scanning tube 2 are less than those received through scanning tube 3, the condenser 8| will receive less charge than that of condenser 82 and the winding will receive a current impulse in opposite direction, causing armature 81 to make contact with contact 88. Relay R3 is then energized over the following circuit: Minus potential 99, relay R3, contact |'--2R5, 3'4R3, contacts 86-81, ground. As soon as R3 energizes it receives holding current over its own contact I '2'R3.

When R3 is energized, impulses transformer IOIl-IOI is disconnected and winding 85 of relay R2 is directly connected to condenser 82 in the same way as winding 84 is connected in parallel with condenser 8|. Simultaneously armature of polarized relay RI obtains ground potential over contact I |--I3'R3 so that polarized relay RI can operate and respond to wave variations from scanning tubes 4 and 5 in the same way as does relay R2 from scanning tubes 2 and 3.

The circuit previously controlled by slow acting cam wheel 82 is interrupted at contact I2- I3'R3. When relay R3 was energized and electric circuits controlling the rapid swinging movements of the bomb through cam wheel 6| were also3 interrupted over contacts I'III' and 8'- 8'R Contacts 4-5' and 8'9 of R3 were closed so that relay R2 now can direct the rudders I I- I2 through relays R6 and R1. The target being located within scanning tubes 2-3 and 4-5 relays RI and R2 now direct the rudders so that the target will be kept in the center between the four scanning tubes so that each pair of tubes always receive equal amount of rays or waves until the target is hit.

In Fig. 6 which represents a wave transmitting device, similar to that one shown in Fig. l ('1). III) is a reflector, III is an antenna and H2 is a transmitter.

Fig. '7 shows a wave receiving device in which I I3 is a reflector, H4 is the antenna, H5 is a modulator, I I6 is an oscillator, I I1 is an intermediate amplifier and H8 is an amplifying device similar to amplifier 39 shown in Fig. 5, to which amplifier 39 switching devices, relays and other equipment shown in Fig. 5 should be connected.

Fig. 8 show a more detailed example of the arrangement shown in Fig. 7. H5 is a known receiving and mixing circuit in combination with the dipole or short wave antenna II4 which latter one is located in the focus of a parabolic reflector H3. H6 is an oscillator circuit of different wave length from the one received. The 0s cillator circuit is connected to the dipole circuit by means of transformer I I9. The received waves and the oscillated waves are mixed in order to obtain an interference wave of suitable wave length to be amplified in amplifier II1. I2I is a rectifier and 39 is the amplifier shown in Fig. 5 to which amplifier the short wave receiving equipment shown in Fig. 8 can be connected instead of to the photocell arrangement shown in Fig. 5.

Fig. 9 shows a detail of the collector arrangement on shaft 83 of Fig. 5, but instead of four scanning tubes and movable disc 25 in Fig. 5 there is only one scanning tube associated with the photocell 8. The scanning tube I24 is excentrically arranged with respect to the photocell 8 which is fixedly attached to the shaft 83 by means of chamber I23 and rotateswith the shaft. I25 and I28 are two collector rings for making electric connection over a grid leak I21 and amplifier 39 to the rest of the wave receiving equipment shown in Fig. 5. By locating the scanning tube excentrically with respect to the shaft the scanning can eflectively be done over the same surface as with four tubes. Instead of a photocell electromagnetic short wave detector equipment can be used in similar manner as that shown in Fig. 9.

In Fig. 10 I 28 and I29 are scanning tubes provided with lenses. I30 is a rotating scanning disc for breaking up the pictures in half or quarter images to be successively projected on the opaque and light-dispersing screens I34. I33 are filters for example to let through only infrared rays. I35 are tubes provided with specially formed reflecting inner surfaces for conducting the resulting images or light waves to the same photocell 6. 6 is a photo-electric cell common to two or four scanning directions and is associated with a. grid leak I21 and a single amplifier 39.

The scanning disc I30 is fixed to shaft I 36 on which it rotates by means of a motor. On said shaft are located collector rings I31 to I to alternatingly connect the amplifier 39 with its photocell to condensers 8I-82 and/or 89-90 in the moment that the corresponding part of the exposed image is allowed to pass through said scanning disc which as shown in Fig. 11 is provided with scanning slits I3I and I32. Scanning slit I32 can successively expose the upper part of the field of vision of scanning tube I28 and the right part of scanning tube I29, while scanning slit I 3I can expose the lower part of scanning tube I28 and the left part of scanning tube I29. Collector ring I31 is metallicly connected to corresponding parts of collector rings I38-I4I as shown in Fig. 11.

I42 is a pendulum provided with a damping device I43 and two electric contacts I44 and I45 adjustable with respect to distance from the lateral extreme position of said pendulum. I46 is another pendulum able to swing in a direction at right angle to pendulum I42 and provided with damping device I41 and adjustable electric contacts I48 and I49.

RI is a relay adapted to switch the steering devices from seeking to fOIlOWlIlg of the target. RII, RI2, RI3 and RI4 are controlling relays. RI and RIB are relays to direct rudder I 50 in one or the other direction by means of armatures I5I and I52 attached directly to the rudder. RI I is a locking relay to lock the rudder l 50 in its neutral position when steering in one or the other direction is not desired. RI 8 and RI9 are relays to direct rudder I 53 in one or the other direction at right angle to the direction of the rudder I50. R20 is a locking relay to lock the rudder I53 in its neutral position.

The device according to Fig. operates in the following way: Upon dropping of the bomb and the eventual closing of a barometer contact (not shown in the drawing) to connect the battery 99 to the device relay RI I, RI 6 and RI1 are energized.

RI1 unlocks the rudder I 50. RI6 pulls down its armature I 52 and rudder I50 is tilted to the right in which position it remains until the oppositely located contact I44 of the pendulum I42 closes a circuit to energize RI3, said relay then obtaining holding current over its contact l-2'. R16 is then deenergized and RI5 energized instead. RI2 is energized. RII is deenergized current with the result that the other rudder I53.

is energized and gives a pull in one direction.

Due to the energizing of RI5 the rudder I50 is gradually pulled to the other side and held there until the other contact I45 of pendulum I42 is closed.- RI 3 is then deenergized becavse it receives current through a' counter-acting winding. RI I isthen energized and RI 2 is deenergized after slow acting. During the slow acting of RI2 RI9 and R20 obtain current so that rudder I53 is unlocked and obtains a pull in the same direction as before.

When the whole field of vision has been searched, the pendulum contact I46-I48 is closed and RI4 is energized and obtains holding current over its contacts I'-2'. Simultaneously contact 5'6'RI4 is opened and contact 3'4RI4 is closed so that next time the pendulum I 42 reaches one of its extreme positions relays RIB and R20 are energized. In said way the rudder I53 is shortly pulled the other way.

In said way the operation continues until the whole field has been searched and the pendulum closes its right contact I46-I49. RI4 is then deenergized by its counter-acting lower winding and so on.

If during the seeking operation an object or the target is encountered, relays RI or R2 are energized in one or the other direction. RIO is energized and receives holding current, whereafter the seeking operation is stopped and the rudder controlling relays are connected directly to the relays RI an R2, and the following of the target takes place in about the same way as previously described in Fig. 5.

Fig. 12 shows a curve of the seeking movement of a bomb just described according to Fig. 10.

Fig. 13 shows a modification of Fig. 10 with the only difference that two photocells are used for searching in four directions, while in Fig, 10 one photocell can be used for searching in all four directions.

In Fig. 13 photocells I56 and I51 are coupled over current source I65, grid leak and amplifier I61 and I66, respectively, to collector rings I58- I63 and relays R2 and R3, respectively, in similar manner as shown in Fig. 5.

In Fig. 15 is shown a device for adjusting the field of vision of the scanning device and also a device to vary the position of the lateral contacts of the two pendulums shown in Fig. 10. I68 is a clock device arranged to start operating at a certain predetermined altitude by means of the electric contacts I69I10 in a barometric device which also can start the operation of the electric devices of the bomb by connecting the current source 99 shown in Fig. 5 or Fig. 10 to the corresponding circuits.

I1I is a shaft to be driven by said clock work. I16 is a holder of contacts I44 and I45 in relation to pendulum I42. The holder I16 is operated by shaft I1I in such a way that the amplitude of the pendulum I42 is diminished proportionately to the descending velocity of-the bomb. I11 is a similar holder mounted at right angle to holder I16 and its pendulum, said holder carrying similar contacts I48 and I49 with respect to pendulum I 46. I12 is a cogwheel attached to shaft HI and drives cogwheel I13 and its shaft I14 with the small cogwheel I15, which in its turn drives cogwheels I33 to regulate the opening of iris shutters I33 and I 34 indicated in Fig. 10.

By means of simple lenses or concave mirrors sufllciently close together so that the picture canbe directly projected on the photocell.

If the bomb should be guided by infrared heat waves that for example are emitted from the funnels of a vessel, a higher degree of ampliflca- V tion than that shown in the figures might be necessary. Such an extra amplification can be obtained by means of so called frequency conversion. The photocell can in such a case in known manner be fed from an oscillator with alternating current superimposed on the direct current normally used. If a vacuum photocell is used the necessary amplification can in known manner be obtained by means of a so-called electron-multiplicator in which the desired sensitivity can be obtained.

In order to increase the velocity of the operating organs gas-filled electron tubes or thyratron relays provided with grids and fed by alternating current can in known manner be used instead of the relays RI and R2 and all relays for the following of the target shown in Fig. 5 or Fig. 10. The grid circuits of the electron tubes can hereby be controlled in known way by means of the voltage from the condensers 8l-82 and 89-90 or directly from the collectors 68-12 or III-Ml.

The seeking operation or the angle that the bomb shall swing in either direction can be controlled in many diiferent known ways. The simplest way should be to give current impulses controlled by a timing device to the motors or relays that control the rudders as above has been mentioned.

When the seeking operation has beenstarted both motors or relays are given an impulse each so that the rudders obtain definite angles with respect to the axis of the bomb. When afterwards the said axis has deviated an angle previously determined with respect to the pendulum, a contact is closed that starts the motor and changes the rudders to a somewhat greater angle the other way due to the fact that the bomb in the meantime has fallen a certain distance. When the axis of the bomb is deviated an angle previously determined with respect to the pendulum in the opposite direction, a new contact is closed that again changes the rudders and so on. The device is, of course, analogous for both movements at right angles to each other. There will only be a difference of the angles that the rudders have to be set with respect to the axis of the bomb. The nearer the target that the bomb arrives, the greater shall the angle be that the bomb shall swing.

If ordinary light or infrared rays shall be used and emission of rays or waves from the bomb itself should not be needed, the receiving devices, for example the scanning tubes, mirrors, lenses, scanning disc, iris-diaphragm, timing device, etc., can be located in the front of the bomb.

Small planes or fins should also be placed in the front so that in combination with the rear fins and rudders the bomb satisfactorily can be Eventually the bomb can be provided in front with a Herzian wave transmitter that also can be used in the infrared region, and the reflected waves detected by electrical means in known way.

The best wave transmitter that will serve under all conditions is an ultrashort wave transmitter. for example a klystron, rhum'batron, magnetron or ordinary triode transmitters in which cases similar devices will serve as receiver of the reflected waves. With such generators and receivers wave lengths from a few millimeters up -to a fraction of a meter can be used for the purpose.

Direct or infrared light can be used for scanning purposes, depending upon the colour and consistency of the object to be scanned. In the following shall be explained when one or the other light waves can be used.

With infrared rays a sharp distinction between light and dark objects can be obtained. Undesirable wave lengths can be absorbed by a suitable filter placed in front of each scanning tube.

The best results are obtained by using infrared waves above 7000 A. or still better between 8400- 9000 A. The reflection increases with increased wave length. At 8550 A. green appears as white, while blue and brown appear as black color, when seen through a suitable infrared filter. In the landscape, grass scrubs and foliage appear very bright, conifers darker, while water generally appears black. The sky usually appears very dark and the clouds white. There is extreme contrast between water and the shore line and solid objects, such as ships on the water, because so'lid objects appear light or of a less dark shade, which is sufficient for our purpose. During daytime a ship or units of a fleet at sea could be easily hit. it a torpedo or bomb is dropped from great height'and the scanning devices be provided with infrared filters as the ship with their solid masses will stand out with a light shade against the surrounding dark sea, even if intervening haze should make the ships invisible for the naked eye at great height. Camouflage paint will be of no avail to protect the ships from detection by the infrared rays.

Airplanes and aircrafts can be easily detected and followed above or below the clouds by visible or by infrared light rays as the metal of aircrafts reflect a substantial amount of rays.

Buildings and concrete constructions such'as fortifications reflect infrared light to a limited degree only. They therefore appear dark when compared, for example, with green vegetation. It should therefore be an easy matter to single out important buildings needed in warfare and destroy them, particularly if located in isolated places, such as ammunition depots, bridges, railroads and the like.

What we claim is:

1. A device for receiving wave energy and for controlling an electrically operated mechanism including two alternatively operating circuits and a member movable in either one of two directions as one or the other of said operating circuits is closed, said device comprising a control circuit, a source of current in said control circuit, a wave energy receiving element connected in series with said source of current to vary the current supplied to said control circuit in dependence upon the wave energy received by said element, a wave energy directing body in front of said receiving element and movable between two positions to admit to said receiving element alternatively the total wave energy from each of two equal parts of a wave energy transmitting field, said two parts being located on opposite sides of a center plane dividing the total wave energy transmitting field, means for moving said body to alternate between said two positions so as to generate in said control circuit pairs of successive current impulses, the two impulses of each pair corresponding, respectively, to the wave energies received from the two parts of the energy transmitting field, and a switching arrangement connected between said control circuit and said two operating circuits for successively switching said control circuit to one or the other of said operating circuits for operating said movable member by means of the difference between the current impulses of said operating circuits as the first impulse of such pair exceeds the second one or vice versa. I

2. A device according to claim 1 in which each operating circuit includes a condenser, said switching arrangement being disposed to close said control circuit across one or the other of said condensers as said body alternates between its two positions, and said switching arrangement includes an electromagnet having two oppositely disposed windings connected across said two condensers, respectively.

3. A device, as claimed in claim 1, in which said single receiving element is a dipole for receiving ultra-short radio waves.

4. In a. self steering aerial carrier of a detonating charge having a movable rudder, an electrically operated current direction sensitive mechanism for moving said rudder in one or the other direction in accordance with the direction of the current supplied to said mechanism, a control circuit, a source of current in said control circuit, a single wave energy receiving element connected in series with said source of current to vary the current supplied to said control circuit in dependence upon the wave energy received by said element, a wave energy directing body in front of said receiving element and movable between two positions to admit to said receiving element alternatively the total wave energy from each of two equal parts of a Wave energy transmitting field, said two parts being located on opposite sides of a center plane dividing the total wave energy transmitting field, means for moving said body to alternate between said two positions so as to generate in said control circuit pairs of successive current impulses, the two impulses of each pair corresponding, respectively, to the wave energies received from said two halves of the energy transmitting field, and a switching arrangement coupled between said control circuit and said mechanism for supplying one impulse of said pair of successive current impulses in one direction and the other impulse in the other direction to said mechanism for driving same in one or the other direction, as the first impulse of said pair exceeds the second one or vice versa.

5. In a self steering aerial carrier of a detonating charge having two independently movable rudders arranged at right angles to each other, two electrically operated mechanisms for moving said rudders, respectively, in one or the other direction in accordance with the direction of the current supplied to such mechanism, a control circuit, a source of current in said control circuit, a single wave energy receiving element connected in series with said source of current to vary the current supplied to said control circuit in dependence upon the wave energy received by said element, a wave energy directing body in front of said receiving element and cyclically movable through four positions to admit to said receiving element in the first and third of said four positions the total wave energy from each of two equal parts of a wave energy transmitting field, said two parts being located on opposite sides of a first center plane dividing the total wave energy transmitting field and to admit to said receiving element in the second and fourth of said positions the total waveenergy from each of two equal parts of. the wave energy transmitting field located on opposite sides of a second center plane dividing the total wave energy transmitting field at right angles to said first center plane, means for moving said body cyclically through said four positions so as to generate insaid control circuit series of four successive current impulses, the first and third impulse and the second and fourth impulse of each series constituting impulse pairs with the two impulses of each pair corresponding, respectiveiy, to the wave energies received fro-m two parts of the energy transmitting field on opposite sides of one of said center planes, and a switching arrangement coupled between said control circuitand said two mechanisms for supplying to each of said mechanisms one impulse of a corresponding pair of successive current impulses in one direction and the other impulse in the other direction for driving said mechanism in one or the other direction as the first impulse of each pair exceeds the second one or vice versa.

6. Aself steering aerial carrier, as claimed in claim 5, including for each rudder an automatic switch for alternately closing and opening the circuit of the associated operating mechanism in order to give the carrier two swinging movements at right angles to each other until the wave energy transmitting field from which the wave energies reaching the wave energy receiving element originate includes the target, and a relay controlled by one of said switching arrangements operative to disconnect at least one of said automatic switches from the associated operating circuits when the impulses of an impulse pair controlling said switching arrangement difler from each other.

7. A self steering dropbomb having a movable rudder, an electrically operated mechanism for moving said rudder in one or the other direction in accordance with the direction of the current supplied to said mechanism, a control circuit, a source of current in said control circuit, a single wave energy receiving'element connected in series with said source of current to vary the current supplied to said control circuit in dependence upon the wave energy received by said element, a rotatable discin front of said receiving element and provided with two arcuate concentric slits angularly displaced relative to each other by the radial distance of one of said slits from the center of said disc being slightly in excess of that of the other slit, said receiving element having a diameter corresponding to the width of both said slits and being disposed eccentrically with respect to said disc so that through each of said slits the total wave energy from an entire and undivided equal half of a wave energy transmitting field is admitted to said receiving element, said two halves being located on opposite sides of a center plane dividing the total wave energy transmitting field, means for rotating said disc so as to generate in said control circuit pairs of successive current impulses, the two impuises of each pair the other impulse alternatively the pulse of said correspondmg, respectively, to the wave energies received from saidtwo halves of the energy transmittin tween said control circuit'and said mechanism for supplying one impulse of said pair of successive current impulses in one direction and in the'other direction to said mechanism for driving same'inone or the other direction, as the flrst impulse of said pair exceeds the second one or vice verse, i

8. A device for receiving wave energyiand tor controlling, an electrically operated current direction sensitive mechanism including a member movable in either of two directions in accordance with the direction of the current supplied to said mechanism. said device comprising a control circuit, a source of current in said control cirin order to retain the rotative axis of said supfleld, and a' switching arrangement coupled be- 7 cult, a wave enery recelvingelement connected 1 of currentto vary the control circuit in dein series with said source current supplied to said pendence upon the wave energy received by said element, a, wavev energy directing bodyin front of said receiving element and movaloleibetween t to said receiving element total wave energy from each of two equal parts of a wave energy transmitting two positions to a fleld, said two parts being symmetrically located I of a center plane dividing the transmitting field, means for on opposite sides total wave energy moving saidbody to cuit'pairs of successive current impulses, two impulses of each pair corresponding,

of the energy transmitting field, and a switching arrangement coupled between said control circuit and said mechanism for supplying one impair of successive current impulses in one direction and the impulse in thetother direction to said mechanism for driving the same in one or the other direction as the first impulse of said pair exceeds the second one or vice versa.

9. A dirigible instrumentality having directional control members, apparatus for automatically guiding the movement of said instrumentality in a predetermined direction with respect to a source of radiant energy comprising a rotatable support having a rotative exis extending ina predetermined relationship with respect to the direction of forward movement of said instrumentality, radiant energy receiving apparatus including a radiant energy receiving member effectively asymmetrically mounted with respect to said axis and on said support for rotation therewith into and out of advantageous energy receiving relationship with respect to said source during each rotation of said support respectively when the axis of rotation of said support is displaced from a predetermined position with respect to said source, said member being adapted to receive energy from said source with uniform facility at all positions when said axis is in said predetermined position with respect to said source, means for drivingly rotating said support, means for converting the radiant energy received by said energy receiving member to electrical current of usable intensity and proportional to the intensity of the received radiant energy, and mechanism electrically connected with said converting means responsive to changes in the value of the current discharged thereby for automatically operating said directional control members in response to the amplitude of radiant energy received by said receiving apparatus respectively, to the wave energies received from the two parts alternate between said two positions so as to generate in said control cirport and accordingly the movement of said instrumentality in a predetermined direction with respect to said source.

10. A self-steering device for aerial carriers, provided with at least one carrying plane and an adjustable rudder mechanism, said device comprising a sender for the emission of ultrashort wave radio energy in the general direction ahead of the carrier, a single receiving element adapted to receive the ultra-short wave'energy emitted by said sender after reflection thereof from a target and its surrounding medium in a limited fleld of vision ahead of the carrier, a radio energy directing body associated with said receiving, element and cyclically movable to admit to said receiving element,

of vision, means for moving said body back andg forth between said two positions so as to pass,

alternately, radio energy impulses reflected from said two equal parts of said limited fleld of vision 1:0 said receiving element in order to generate varying potentials in the latter, and control means for said ruddermechanism operatingin function of the potentials, generated in said receiving elements to steer the carrier towards the target.

11. A self-steering comprising a sender for the emission of ultrashort wave radio energy in the general direction ahead of the carrier, 9, single receiving element adapted to receive the ultra-short wave energy emitted by said sender after reflection thereof from a target and its surrounding medium in a limited field of vision ahead of the carrier, a radio energy directing body associated with said receiving element and cyclically movable to admit to said receiving element, alternatively, the total radio energy from each of two equal parts of said limited field of vision located on opposite sides of a center plane dividing said total limited field of vision, means for moving said body back and forth between said two positions so as to pass, alternately, radio energy impulses reflected from said two equal parts of said limited field of vision to said receiving element, means for converting the radio energy impulses received by said receiving element to electrical current impulses of usable intensity and proportional to the received radio energy, an electrically operated, current direction responsive device for controlling said rudder mechanism in one o the other direction, and switching arrangement coupled between said converting means and said rudder controlling mechanism for supplying to the latter one of a, pair of successively receiving current impulses in one direction and the other impulse in the opposite direction in order to steer the carrier towards said target in function of the variations of the radio energy received from said two equal parts of the fleld of vision.

12. A target seeking device for aerial carriers provided with at least one carrying plane and an adjustable rudder mechanism, comprising a single receiving element adapted to receive radiant energy from a target in a limited fleld of vision ahead of the carrier, means for converting the radiant energy received by said receiving element to electrical current of usable intensity, at

7| least one electric rudder operating device, an

alternatively, the total radio energy from each of two equal parts of said device for aerial carriers provided with at'least one carryingplane and an adjustable rudder mechanism, said device impulse generator normally coupled to said rudder operating device and adapted to transmit to the latter a series of impulses of alternately opposite polarity for operating it in one and the other direction in accordance with the polarity of the impulses supplied thereto so as to give to the carrier a swinging movement for seeking the target in a plurality of directions until such target appears in said limite field of vision and an electric switching device coupled to said energy converting means and adapted to disconnect said impulse generator from the rudder operating device and to couple the latter to said energy converting means upon reception of radiant energy from a target in said limited field of vision by said receiving element.

13. A target seeking device for aerial carriers provided with two carrying planes and two ads justable rudders disposed at an angle to each other, said device comprising a single receiving element adapted to receive radiant energy from a target in the limited field of vision ahead of the carrier, means for converting the radiant energy received by said receiving element to electrical current of usable intensity, for each rudder in electric rudder operating device, electric current impulse generating means coupled to said rudder operating devices and adapted to transmit to each of the latter a series of impulses of alternately opposite polarity for moving the rudders alternately in one and the other direction in accordance with the polarity of the current impulses supplied to said devices so as to give to the carrier two diiferent simultaneous swinging movements for seeking the target in a plurality of directions until such target appears in said limited field of vision, and an electric switching device coupled to said energy converting means and adapted to disconnect said electric impulse generating means from said rudder operating devices and to couple the latter to said energy converting means upon receipt of radiant energy from a target in said limited field of vision by said receiving element.

14. A target seeking device for aerial carriers provided with at-least one carrying plane and an adjustable rudder mechanism, comprising a 18 receiving element adapted to receive radiant energy from a target in a limited fiel of vision ahead of the carrier, means for converting the radiant energy received by said receiving element to electrical current of usable intensity, at least one electric rudder operating device, an impulse device normally coupled to said rudder mechanism for operating the same alternatively in opposite direction in order to give to the carrier a swinging movement for seeking the target in a. plurality of directions until such target appears in said limited field of vision, and an electric switching device coupled to said energy converting means and adapted to disconnect said impulse device from the rudder mechanism and to couple the said electric rudder operating device to said energy converting means upon reception of radiant energy from a target in said limited field of vision by said receiving element.

HELGE FABIAN ROST.

KARL HARRY THUNELL.

STEN DANIEL VIGREN.

PER HARRY ELIAS CLAESSON.

REFERENCES QITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,388,932 Centervall Aug, 30, 1921 2,109,475 Fanning Mar. 1,.1938 1,303,105 Murdock May 6, 1919 2,176,469 Moueix Oct. 17, 1939 1,892,431 Hammond Dec. 27, 1932 1,958,893 Kintner et al May 15, 1934 1,384,868 Sperry et a1 July 19, 1921 1,387,850 Hammond, Jr Aug, 16, 1921 2,165,800 Koch July 11, 1939 2,003,661 Bassett et a1. June 4, 1935 FOREIGN PATENTS Number Country Date 441,866 Great Britain Jan. 27, 1936 354,768 Italy Dec. 7, 1937 352,035 Great Britain June 22, 1931 

